This non-provisional application claims priority under 35 U.S.C. xc2xa7119(a) on Patent Application Nos. 2001-160048 and 2001-171244 filed in Japan on May 29, 2001 and Jun. 6, 2001, respectively, the entirety of which are hereby incorporated by reference.
1. Field of the Invention
The present invention relates to a vehicular remote control lock apparatus that has a lock control means for controlling an actuator for actuating and de-actuating a steering lock device of a vehicle by means of a remote control transmitter. The vehicular remote control lock apparatus saves power by intermittently supplying standby current to the lock control means while the steering lock device is actuated. In the present invention, the remote control transmitter may be capable of transmitting a starting code and an ID code by operation of a control button thereof.
2. Description of Background Art
A remote control lock apparatus for actuating and de-actuating a door lock device by operating a remote control transmitter external to a vehicle is well known in a four-wheel vehicle. In such a remote control lock apparatus, a lock control means receives an ID code transmitted from the remote control transmitter, and then compares the ID code with an ID code prestored therein. When the ID codes coincide with each other, the door lock device is de-actuated, thus preventing theft or unpermitted use of the vehicle. For this purpose, it is necessary to supply a standby current to the lock control means at all times while the occupants of the vehicle are away from the vehicle. Since supplying the standby current to the lock control means for a long time period increases a load on the battery; however, power is saved by intermittently supplying the standby current to the lock control means. For example, by intermittently driving an ID code obtaining means of the lock control means, it is possible to reduce the standby current to about 1.5 mA. By intermittently driving both the ID code obtaining means and an ID code verifying means of the lock control means, it is possible to reduce the standby current to about 1.0 mA.
In addition, a remote control lock apparatus for actuating and de-actuating a steering lock device by operating a remote control transmitter external to a vehicle is known in a motorcycle. In such a remote control lock apparatus, a lock control means receives an ID code transmitted from the remote control transmitter, and then compares the ID code with an ID code prestored therein. When the ID codes coincide with each other, the steering lock device is de-actuated, thus preventing theft or unpermitted use of the vehicle. For this purpose, it is necessary to supply a standby current to the lock control means at all times while the occupant of the vehicle is away from the vehicle. Since supplying the standby current to the lock control means for a long time period increases a load on the battery; however, power is saved by intermittently supplying the standby current to the lock control means.
In a first conventional example shown in FIG. 8, a lock control means of a remote control lock apparatus includes an ID code obtaining means and an ID code verifying means. In order to save power, the ID code obtaining means is supplied with an intermittent standby current. A starting code signal is transmitted after a control button of a remote control transmitter is pressed and then released. An output time A of the starting code signal coincides with a cycle A in which the intermittent current is supplied to the ID code obtaining means. Therefore, a state in which the ID code obtaining means is supplied with current always occurs during the period when the starting code signal is transmitted. Accordingly, the starting code signal is received reliably during the period. When the starting code signal is thus received, the ID code obtaining means, which has been supplied with the intermittent current, is then supplied with a continuous current. Therefore, an ID code signal transmitted by the remote control transmitter following the starting code signal is received reliably by the ID code obtaining means. The ID code verifying means compares the ID code obtained by the ID code obtaining means with a prestored ID code. When the ID codes coincide with each other, an actuator is activated to de-actuate a steering lock device.
The first conventional example shown in FIG. 8 transmits the starting code signal and the ID code signal when the control button of the remote control transmitter is pressed and released in a mere instant. In a second conventional example shown in FIG. 9 the starting code signal and the ID code signal are transmitted after the control button of the remote control transmitter continues being pressed for a certain time (for example 0.5 sec to 1.0 sec) and then released. Otherwise, the second conventional example functions in the same manner as the first conventional example.
When the remote control lock apparatus of the four-wheel vehicle is applied to a steering lock device of a small vehicle such as a motorcycle or a motor tricycle, problems arise since the battery of the small vehicle has a small capacity. Accordingly, the battery can be exhausted even if power is saved by the method of intermittently supplying standby current. In order to prevent this, decreasing an intermittent supply ratio (ratio of a time for which the standby current is supplied to a total time) of the standby current is conceivable. However, this lengthens the time intervals at which the standby current is supplied, thus resulting in a longer response time between the operation of the remote control transmitter and the actuation of the steering lock device. As another method, it is conceivable that the supply of the standby current to the lock control means is interrupted when the vehicle is left unused for a certain time. However, this naturally makes it impossible to actuate the steering lock device by means of the remote control transmitter when the vehicle is used the next time, and also requires an operation for restarting the lock control means by using a starting switch or the like.
The present invention has been made in view of the above, and it is accordingly an object of the present invention to prevent exhaustion of the battery by minimizing the standby current while maintaining maximum response of the remote control lock apparatus.
The first conventional example transmits the starting code signal and the ID code signal when the control button of the remote control transmitter is pressed and released in a mere instant. Accordingly, if the remote control transmitter is carried in a pocket or a handbag, the steering lock device may be de-actuated unintentionally if the control button is pressed by mistake. In the second conventional example the remote control transmitter does not transmit the starting code signal and the ID code signal unless the control button of the remote control transmitter is pressed continuously for a certain time. Accordingly, although there is no fear of the unintentional de-actuation mentioned above, a response time b between the pressing of the control button and the de-actuation of the steering lock device is longer than a response time a of the first conventional example, thus resulting in degradation in response.
The present invention has been made in view of the above, and it is accordingly an object of the present invention to ensure maximum response in de-actuating the steering lock device while preventing erroneous activation.
In order to achieve the above objects, according to a first aspect of the present invention, a vehicular remote control lock apparatus includes a lock control means for controlling an actuator for actuating and de-actuating a steering lock device of a vehicle by means of a remote control transmitter. Power is saved by intermittently supplying a standby current to the lock control means while the steering lock device is actuated. A plurality of modes having different intermittent supply ratios of the standby current are selectable. A mode for shorter standby time of the lock control means has a higher intermittent supply ratio while a mode for longer standby time of the lock control means has a lower intermittent supply ratio.
With the configuration described above, when power is saved by intermittently supplying the standby current to the lock control means while the steering lock device is actuated, it is possible to enhance the response in de-actuating the steering lock device by increasing the intermittent supply ratio in the mode for short standby time. This does not particularly necessitate a saving of power. However, it is possible to effectively save power by decreasing the intermittent supply ratio in the mode for long standby time, which particularly necessitates a saving of power. It is thereby possible to reconcile the response in de-actuating the steering lock device with the saving of power. In addition, since the supply of the current to the lock control means is not completely interrupted even in a long standby time, a special operation for restarting the lock control means is not required.
Furthermore, according to a second aspect of the present invention, in addition to the configuration of the first aspect of the present invention, a vehicular remote control lock apparatus is provided, wherein the lock control means includes: an ID code obtaining means for receiving an ID code transmitted from the remote control transmitter; and an ID code verifying means for comparing the obtained ID code with a prestored ID code. In addition, in a normal mode for short standby time of the lock control means, the ID code obtaining means is driven intermittently and the ID code verifying means is driven continuously. However, in a long leaving mode for long standby time of the lock control means, both the ID code obtaining means and the ID code verifying means are driven intermittently.
With the configuration described above, only the ID code obtaining means is driven intermittently in the normal mode for short standby time of the lock control means. However, both the ID code obtaining means and the ID code verifying means are driven intermittently in the long leaving mode for long standby time of the lock control means. It is therefore possible to save power more effectively in the long leaving mode for long standby time, which particularly necessitates a saving of power.
Furthermore, according to a third aspect of the present invention, a vehicular remote control lock apparatus includes a lock control means for controlling an actuator for actuating and de-actuating a steering lock device of a vehicle by means of a remote control transmitter capable of transmitting a starting code and an ID code by operation of a control button thereof. Power is saved by intermittently supplying a standby current to the lock control means while the steering lock device is actuated. The remote control transmitter transmits the starting code immediately after the control button is pressed, and when the control button remains pressed after the transmission of the starting code is completed, the remote control transmitter transmits the ID code.
With the configuration described above, the starting code is transmitted immediately after the control button of the remote control transmitter is pressed. When the control button remains pressed after the transmission of the starting code is completed and the lock control means is started, the ID code is transmitted. The actuator is then activated to thereby de-actuate the steering lock device of the vehicle. Therefore, since the ID code is not transmitted when the control button is pressed only momentarily, there is no fear of erroneously activating the actuator. In addition, since the starting code is transmitted immediately after the pressing of the control button, the response time between the pressing of the control button and the activation of the actuator can be reduced as compared with a conventional example that transmits the starting code after the control button is pressed and then released.
It is to be noted that a lock/unlock button 14a in the following examples corresponds to the control button in the present invention. Also, the foregoing word xe2x80x9cimmediatelyxe2x80x9d considered to include passage of an infinitesimal time.
Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.